Is This Why We Are Alone?

Our giant galaxy is at least ten billion years old. It has 100 billion stars. Many of them second generation stars. It would seem most stars have planets, and many of these fall in the so-called habitable zone. In multiple star systems, some planets will fly away. Still, there may be 40 billion potential Earths in the Milky Way. Yes, and No.

However, ten billion years, over (more than) 100 billion planetary systems, gives more than plenty of time for a civilization to expand throughout the galaxy. Yes, throughout the galaxy. So aliens should have visited Sol, but all indications are that they did not: life on Earth is indigenous to Earth, or the Earth-Mars system.

Why We Are Alone: Earth Is Both Very Watery & Very Radioactive, Deep Inside. The resulting massive tectonic recycling creates a massive churning of carbon, preventing unbearably hot Earths, or snowball Earths escapades into conditions reducing life to bacterial life….

How did Earth get her enormous radioactive fission core? A mystery. It seems that Venus did not. Indeed, Venus has no self-generated magnetosphere (differently from Mercury, Jupiter, or Saturn; Mars is too small to have a churning metallic core, so has no magnetosphere, thus CMEs tear the Martian atmosphere away, in particular water). Instead Venus has an induced magnetosphere. A pathetic device that could not prevent Venus from being deprived of all its hydrogen, hence water, torn by the solar wind, especially during Coronal Mass Ejections CME).

The Sort of Comet from Hell On Top Is Venus. Earth, The Blue World, Is Below. Earth, With Her Complex Magnetosphere Created By Her Churning Liquid Metal Radioactive Core: Part Of The Reason Why Venus Melts Lead, & Earth Harbors Civilization. [Courtesy ESA.]

Travelling throughout the galaxy is already within our reach. Nuclear fission rocket engines were very successfully tested in the 1960s. They would allow us, should we decide to do so, to make spaceships going through the galaxy at 100 kilometers per second.

That’s 1/3000 of the speed of light. The galaxy is 100,000 light years across. So, with existing technology, primitive technology of the 1960s, we could cross the galaxy in 300 million years.

Now, of course, faster tech is perfectly imaginable, such as thermonuclear propulsion. (Thermonuclear propulsion may be easier to achieve than a contained nuclear fusion motor, because containment is the most major problem of controlled fusion; an uncontained engine would be half way between an H-bomb and ITER, and pure fusion is clean; actually NASA finances, all too modestly, such research.) Whereas the temperature in a fission reactor will be at most 3000 degree Centigrade, thermonuclear fusion could reach 100 million degrees, enabling an impulsion 10,000 times greater. Thus mastery of thermonuclear fusion would allow to cross the galaxy in a few million years.

So, if there was a civilization barely more advanced technologically than we are, it would have established a galactic empire in a few million years. It should have visited our blue planet, detectable from thousands of parsecs (with existing technology not deployed by the grotesque, imbecilic plutocrats who rule us through those countless obsequious greedy critters which most politicians are).

The definition of the traditional habitable zone is naive: it is only about temperature. Temperature has to be just right, so that there is liquid water on the surface. And, naively, that is thought to mean holding a particular distance relative to a star. However it takes more than temperature to keep a planet habitable. Mars had an ocean, but lost its surface water, a little bit at a time, from repeated Coronal Mass Ejections (CME). A CME consists in a super active flame jetting out from the sun. If a CME hit Earth now, much, if not most electric circuitry on Earth would fail.

Radioactive Elements, Being The Densest, Sink Towards The Star During The Planetary System Formation. (Observed So far.). Oxygen & Hydrogen, With 5% Average Nuclear Mass Migrate Out

Venus does not have a strong magnetic field either. Why? We don’t know. OK, Venus doesn’t rotate very much.

Earth, though rotates mightily, stabilized by her big Moon, and her high density (because of pressure, Earth is denser overall than Mercury, although the latter seems to be a planetary core…)

The Earth magnetic field is a shield, and it is created by the nuclear fission engine at the core of the Earth (it makes the surface of Earth’s core hotter than the surface of the sun! That makes a metallic iron ocean above churn violently, and generate the magnetic field… And also plate tectonics, which recycles carbon deep in the mantle, preventing it to sit in the atmosphere, as in the case of Venus!)

Thermal hot spots are indirectly nuclear fission activated, but before three billion years ago, thermal hot spots driven directly by ionizing and mutagenic radiation from surface nuclear reactors, were probably ubiquitous. Thus, to have the four billion of years needed to develop ADVANCED native life, with all the mutations it entails, one needs to have both a nuclear reactor inside a planet AND the planet enjoying surface water for four billion years.

A tough, and rare call. Moreover, life has to escape crashing dwarf planets, migrating Super-Jupiters, super stellar Coronal Mass Ejections (all the more frequent in Red Dwarfs), close encounters with passing stars, gamma ray bursts, supernovae, colliding black holes, super stars exploding, central galactic black hole eruption (many of these catastrophes were very recently revealed, and did not percolate yet to We The People). To let life develop over four billion years, we need an extraordinary confluence of circumstances. (And when I say four billion, that’s generous: the “Cambrian explosion” when animals appeared in a great number of types of species, was only 540 million years ago. Moreover, life on Earth may have been accelerated by being started on Mars, at a time when Earth was still way too hot for sophisticated chemistry, and then transported by meteorites (that this strange method of life transportation could still be done to this day, has been demonstrated, by carefully analyzing meteorites of Martian origin).

Life, Sustained Long Enough For Advanced Animals? Unlikely. The Milky Way Is Ours. And Oblivion Watches Over Us, Not Tenderly.

So expect life to be very frequent in the galaxy, and habitable planets to be many. As long as one is talking about bacterial life functioning on DNA like system (the details will be different, as post-DNA life was already synthesized in the lab!)

But little green men, Kzins and Doctor Spock? Not a chance. If they happen some day, they will be our descendants. That we are alone changes the stakes. We are not just threatening civilization, with our childish, yet lethal and atrocious antics, but we are threatening to annihilate the one and only crown of creation.

31 Responses to “Is This Why We Are Alone?”

Reading this post I remembered reading Ian Stewart’s 18th chapter of Mathematics of Life titled Is Anybody Out There?.
So I would respectfully disagree with your conclusion
one needs to have both a nuclear reactor inside a planet AND the planet enjoying surface water for four billion years.

Instead of ‘nuclear reactor’ is more pertinent to talk about ‘plate tectonics’ and now we have evidence, that plate tectonics is quite common between exoplanets, esp. so called super-earth.
As for ‘surface water’, what about extremophilles, or less extravagant, deep ocean life?

Considering cosmic hazards, like supernova explosions, gamma ray bursts, asteroids etc, they are very difficult to quantify, but in view of astronomical number of habitable exoplanets (and exomoons) that doesn’t seem to be very serious problem.

That still leaves open question: Where are They?
Maybe they visited earth some million years ago (Daeniken anyone?) and didn’t fancy it much.
Or maybe they just catched human generated EM vawes and are in preparation for ‘Expedition Gaia’ 🙂
Or maybe their intelligence is completely incomparable to ours, something like ours and ants’ …

I know Ian Steward… but never read his book. The Ian I know is a famous mathematician, and he has written general books. I am a mathematician too… Extremophiles are First Life, so to speak. They sit pretty below volcanoes… Resisting arrest. Could we have a civilization based on extremophiles? I doubt it. Heat is agitation, too much agitation prevents complicated structures. Most proteins get cooked at 60 C… That’s why I eat raw salmon, and raw tofu.

That “plate tectonics” has been detected on Super Earths is news to me. But things are changing fast… I would assume one would find it easier to detect CH4, or O2.

“Plate tectonics” is another word for nuclear reactor. It’s just used not to scare children. I had major fights with eminent geophysicists about the Earth nuclear reactors. Some turned blue in the face, never wanted to be friends again, came ten years later to make amends. I am happy to have infuriated an eminent climate scientist Friday about his climate denial too…

Anyway my argument, as presented is that being in the water belt is not enough. One needs to be in the radioactive belt too. Io does get hot from gravitational massage, but Europa has a 50 kilometers thick icecap. So organic materials (??????) leaks on surface… but that’s not really civilized…

The argument that they are so super smart, those little green spirits, that they leave no trace, can be held, and is less implausible than Muhammad going to Jerusalem on a flying horse, I must admit… Still, more people believe in the flying horse…

Maybe would be productive if we identify three important steps toward intelligence:
1. origin of Life
2. origin of multicellularity
3. intelligence alla Homo Sapiens
(maybe origin of photosynthesis could be added)
First step occured more or less quite early in Earth’s history
Second step is usually connected with Cambrian explosion about 542 mya.
And third step happened in geological present.
So the first step seems to me the least problematic. The second step takes 3.5 billions and the third 0.5 billions.
If we repeat this story in many thousand or even millions exoplanets and exomoons in the Universe, we would see some variation. I don’t see any wishfull thinking in asserting that in some examples we would see this numbers much lower, in the range of 1 billion years or even considerable less.

I saw it. Indeed typical of all too many academic papers, just telling what others do, and the opposite. To avoid nestling of comments, I will answer your observation separately, in a non nestled comment.
PA

The general area is highly contentious. Early life left no structural traces we can now discern. It’s detected mostly by its lipids, or bacterial mats like structures. As far as we can see, Archaea and Bacteria are no more related to each other than they are to Eukaryotes.

In any case, my point was about advanced animal life, 3.5 billion years removed, at least. The point was to have such a stable environment for 4 billion years (keeping in mind Mars may have accelerated Earth’s life!)

Appropriately alarmed by your comment, I added a sentence or two about the connection between the Earth nuclear reactor and the magnetosphere and plate tectonics… For those who don’t know about the relationships…

To Darko: First I feel that speculating on life not based on water is silly. Hydrogen and oxygen are the most abundant (Hydrogen, with 75% of the universe) and third most abundant (Oxygen, 1%).

Helium and Neon, the second and fifh most abundant, are chemically supine, and don’t count. The fourth most abundant is Carbon, the sixth, Nitrogen. Then there is Silicon (quartz, granite)…
So that’s what Earth life is based on, and so it is around the universe, end of story.

The big change on Earth was the switch from CH4 based atmosphere (reducing) to oxygen laden (O2 being generated by blue-green ague). It caused snowball Earth. Twice at least.

Disaster was barely avoided.

The Cambrian explosion is associated to the appearance of big brainy carnivorous animals.

That the evolution of life can go faster is pure speculation. Life on Earth is so complex that its origins have disappeared completely, and look miraculous. Also don’t forget panspermia from Mars, accelerating the process by probably half a billion years (we have evidence for that). The Mars-Earth situation is special, Mars being out there, and much smaller, but still occasionally close, it could cool fast, evolve early life, and transfer it.

I have explained in 40 billion Earths, it’s very unlikely that catastrophic events can be avoided. Already, all the inner parts of the galaxy are probably wiped out of proto-animal each time the core erupts. Last big eruption was less than 2 millions years ago, and the shock wave is by the Magellan clouds right now.

Well, according to some people waterless life is completely probable, see f.e. this and I quote
All three of these candidates [Mars, Europa, Enceladus] rely on the assumption that liquid water is an important factor in determining whether a world could host life, but that doesn’t rule out the existence of lifeforms on waterless worlds. Indeed, it’s just as fascinating to speculate on the nature of water-independent creatures as it is to imagine water-dependent ones, which is what makes Titan, Saturn’s largest moon, such an interesting candidate for exploration.

“Titan [has] surface seas of methane and ethane, and an extensive nitrogen atmosphere,” said Lunine. “Life in the seas—should it exist—would utilize a different biochemistry than life which arose and evolved in liquid water.”

I don’t see any logical necessity, why Mars could accelerate life for half a billion years. What evidence do you have in mind?

And now for something that we should have been asked at the beginning: What is null hypothesis? In my mind there is no doubt: our planetary system is typical. By that I don’t mean only standard ‘real estate’, like sun, planets and moons, but also comets, asteroids and cosmical neighbourhood (like supernova explosins, gamma ray bursts etc).
If so, it logicaly follows that there is a vast number of planets nad moons, where time from beginning of Life (or more precisely, from begining of cinditions supporting life) to intelligence is less than 4 billions years and in some cases much less.

Life not based on water-carbon is unlikely for a whole bunch of reason I alluded to. Abundance of elements, and wealth of chemistry between OC and 50 C. Others can speculate all they want about fluor based silicon life somewhere, it’s not going to happen. Nor life at low temperature.
On the other hand, there is no doubt that some of Earth life could adapt, or be adapted to Mars, Europa, Enceladus, etc…

Mars accelerated because the reason I gave: it cooled faster, much faster than Earth. It’s further out, it has a much higher surface to mass ratio, it has no, or not much of a radioactive core, etc… Life could have started on Mars maybe 4.5 billion years ago, just 40 million years after a magma boiling Earth got itself together. Earliest (controversial) trace of life on Earth are at 4.1 billion. Before that Earth was probably too hot. Too bad for those magma swimming science fantasy fishes…

Some French guy named astrobiology nearly a century ago. Speculation was rife then. Now we know the abundance of elements, so I think what we’ve got is what comes naturally.
Life going from planet to planet has been demonstrated from Mars TO Earth (the reciprocal would be much more difficult). BTW, star clusters are so dense that it would be easy for life to hop from star to star (let alone civilization!). Fred Hoyle suggested this for Earth life, in the 1950s., it’s called panspermia.. But now we know Earth life is only about the Mars-Earth system. (Or, at least, I know… ;-)) No need for it to come from afar. Getting a meteorite from Mars to Earth has happened millions of time. From Proxima Centauri? No.

Yes, learning from mistake works, as long as one survives them without being affected much. Not the case when one is dead. The NYT article shows that the rise of sea level is not normal flooding: vegetation does not survive high tides. And, as the “Euroskeptics” will find out very soon… (Sorry to get you launched, hahaha)

I am convinced that a lunatic state ( of which there is no lack of choice) with nuclear weapons is the biggest danger we face. Since O’Blather cancelled sanctions against Iran they have been buying millions of dollars worth of arms from Russia. The Saudis (who also think they have God on their side) are also claiming to have nuclear weapons. What better way to go out than with a big bang and destroy both Israel and yourself doing Allah’s work and shouting “Alluha Akhbar” at the same time. And the first to go gets the best virgins …..

There is another point: high-technology civilizations are inherently self-destructive. If you take a look, two major problems go hand in hand with technological advance: increase in resource consumption and reduced natality. Either of these can destroy a civilization over a time. And then there is pollution, superbacteria (created by industrial animal farming – antibiotic resistence in bacteria appears when said antibiotic is introduced to farms, and no sooner. Hence I’d say that meat eating qualifies as a crime against humanity.) etc.

Dear Picard: Yes, indeed. I used to think this, too. However, it’s not clear to me what would happen. OK. Suppose the worst. The worst is the greenhouse effect running amok. So say we gain nine (9) degrees CENTIGRADE. This is the natural trajectory we are on at this point. The Malthus curve (so to speak, I just made up the term).
Result: sea level goes up near 80 meters within 2 centuries. Three billion people are displaced. Massive nuclear and molecular biological war ensues.
A probable effect would be massive technological progress, from thermonuclear fusion, to new speciation within Homo (to make superkillers, or super-resistant human beings).

Say things go as bad as possible. One has to suppose that those with the fanciest tech would survive. Reminder: nuclear rocket engine were made in the 1960s, and worked aplenty. Seeing things develop towards war, bases on the Moon, Mars, or even Ganymede could established (using nuclear power).

End result: maybe only a few hundred million high tech survivors, maybe prone to cannibalism, but otherwise very functional.

Thus what would come out would be a fierce, ferocious, much more high tech civilization.

I do not make it all up. The Nazis wanted to kill various “undermen” (“Untermenschen”): Jews, Gypsies, Slavs… Or people they feared, foremost the French. However, once the Nazis had been defeated for more than a decade, the MAD doctrine appeared, Mutually Assured Destruction. MAD was after killing roughly EVERYBODY. No more subtle discrimination, as with the Nazis. Thus, one sees that, philosophically, humanity was already partaking in the post-apocalyptic doctrine.

An alien civilization may well go through such a phase. Even if 99% of humanity died violently, a perfectly sustainable 75 million people would be left, plenty enough to make civilization go forward. Moreover, we already have, using nuclear propulsion, the capability of conquering the solar system (we just don’t deploy it yet). Hence we should be able to spread beyond one planet. An alien civilization at our stage, we may argue, might be very hard to annihilate.

[I do know this thesis of the resilience of an advanced civilization goes against accepted wisdom… But that’s my job…]

Problem is that high technology is inherently fragile, as is the knowledge necessary for its maintenance. Greenhouse effect is not a major danger: it happens relatively slowly, so we can adapt to it (at least until the Siberia farts its methane). Floating and/or undersea habitats are always a possibility, and humanity can easily solve its food problems by going vegan/vegetarian. Algae are edible.

However, there are many other possibilities. NBC war as you noted. In fact, many of the more dangerous new diseases were likely created in laboratories and released in the wild for purposes of testing. And large shifts in international order are typically followed by equally large wars. If majority of people were to get killed in such a war, it is entirely possible that advanced civilization would fall apart: unless survivors were in highly concentrated groups, maintaining existing technology would become impossible. Biological agents could continue to wreak havoc for years after the war. Of course, an advanced civilization preparing for such a scenario has ways of reducing the damage enough for it to become a non-issue… but humans have a tendency to ignore problems and hope they will go away rather than adressing them.

[…] and the like have more than twice the density of iron (19.1 versus 7.8… g/cm^3). I believe Earth is in what I call the Radioactive Zone. Not just the Water Zone, aka the “Habitable Zone”. According to me, without radioactivity at […]

A few comments. As you say, Patrice, we don’t know why Venus does not have a magnetic field, but the fact it has negligible rotation may have something to do with it.

Why no plate tectonics. Maybe negligible rotation, so minimal Coriolis forces generated in places. Maybe negligible water, because the water content might provide some lubrication to the descending plate. Maybe too little felsic rock (continents) which tend to offer basalt a reason to go downwards. Maybe the composition is such that it can’t make eclogite (a very dense material) from its basalt, in which case there is no pull subduction. This is definitely the reason why Mars does not have it – the excess of iron oxide in its basalt means eclogite cannot form. So, in short we don’t know.

However, I am reasonably confident as to why there is so much CO2 in the Venusian atmosphere: no significant water, and there never was. There is nothing to weather rocks and deposit carbonates. Earth has almost was much CO2 near the surface, but almost all is locked away as lime, dolomite, etc.

There is no reason to believe Venus does not have internal radioactive heating. There is evidence of really massive volcanic eruptions in the past, which is at least suggestive of internal heating.

Thanks for the excellent suggestions, Ian.
Clearly, if a planet doesn’t rotate, the ocean of melted iron will not churn, so no magnetic field…
Very good point about the CO2 being locked here on Earth, in all these rocks… So it’s related to the lack of water… and that from being too close to the star…
So basically you say lack of water was key to hostile CO2 atmosphere…

Mars, on top of the geological reason you gave… which I don’t know enough to appreciate… was also too small to develop a big enough Carnot engine of rock churning… Venus geology is not clear to me… at least as far as massive volcanism is concerned.

Indeed! There is a European mission going to Venus, it’s going to take years, using planet assist to… BRAKE!
I think your idea that Venus got different because it was too hot for water to start with is spectacular…. But I have a problem with the fact the Sun (Sol) output is supposed to be 25% less 4 billion years ago… So it should have allowed water… Venus being at the limit of habitable zone…???